%% The MIT License
%% 
%% Paralog is licensed under the MIT License.
%% 
%% Copyright (c) 2008 Robert Ahrens <mindangels@yahoo.com>
%% 
%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%% 
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%% 
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.
%% 

%% @author Robert Ahrens <mindangels@yahoo.com>
-module(pls).
-include("pl_syntax.hrl").

-export([
         project/0,
         p/1,
         v/1,
         get_var_maker/0,
         anon_var/0,
         rule/3,
         call/2,
         fact/2,
         is_primitive/1
        ]).


project() -> ?PROJECT.


p(X) when is_atom(X) -> ?P(X).


v(V) when is_atom(V) -> ?v(V).


get_var_maker() -> fun v/1.


anon_var() ->
    ?v(list_to_atom(erlang:ref_to_list(make_ref()))).


rule(Name, Head, Body) 
  when is_atom(Name) andalso is_list(Head) andalso is_list(Body) ->
    ?rule(Name, Head, Body).


call(Rule, Args) 
  when is_atom(Rule) andalso is_list(Args) ->
    ?call(Rule, Args).


fact(Name, Head) 
  when is_atom(Name) andalso is_list(Head) ->
    ?fact(Name, Head).


is_primitive(P) -> ?is_primitive(P).
     
    
    
